In the case of composite components made of a metal part and a plastics, e.g. molded, part which are connected to each other, the problem often arises that stresses or deformations occur due to the different coefficients of linear thermal expansion of the two materials. If, for example, polycarbonate sheets are used instead of glass for the glazing of vehicle roofs, the polycarbonate sheets exhibit substantially greater deformation when subjected to heat than do glass sheets, due to the very different coefficients of linear thermal expansion of polycarbonate and steel. Polycarbonate sheets are bonded to the steel roof of the vehicle using, for example, an adhesive, whereas glass sheets are generally fixed in place using clamping seals or an adhesive. When polycarbonate sheets expand under the effects of intense heating, the adhesive cannot compensate sufficiently for the linear thermal expansion and the sheets buckle. This problem of deformation does not occur with glass sheets due to the smaller difference between the coefficients of linear thermal expansion of glass and steel and the greater inherent rigidity of glass as compared with polycarbonate.
The object of the present invention is, therefore, to provide a composite element comprising at least two parts with different coefficients of linear thermal expansion, in particular a shaped part made of metal and a part made of plastics, e.g. a molded part, in which the parts are connected to each other in such a way that undesired deformations of the parts, in particular of the plastics part, as a result of the different linear thermal expansions of the parts is minimized, preferably prevented. At the same time, the external forces which occur such as, for example, the stresses caused by strong winds in the case of vehicle glazing, should absorbed so that deformation due to mechanical effects and the natural frequency characteristics are not impaired.